RosLiCamFuse (ROS Lidar Camera Fuse)

This tool reads the images and point clouds' messages from a rosbag, synchronizes them, and applies the calibration parameter to color the point clouds base on images.

Build

Make sure you installed:

sudo apt install libpcl-dev

and

OpenCV 3.4.2

Then, move the repo to the directory src in your catkin workspace. Example:

mv lidar_cam_proj catkin_ws/src

Finally, install the package

cd catkin_ws
catkin_make

Quickrun Examples

rosrun lidar_cam_fuse fuse _out_dir:="/home/ductm/catkin_ws/src/lidar_cam_proj/data/" _bag:="/home/ductm/ros1_bags/sample.bag" _cam_topic:="/camera/tricam/mid/image_raw/compressed" _lidar_topic:="/lidar/points_raw" _extrinsic:="/home/ductm/catkin_ws/src/lidar_cam_proj/calib/extrinsic.txt" _intrinsic:="/home/ductm/catkin_ws/src/lidar_cam_proj/calib/intrinsic.txt" _distortion:="/home/ductm/catkin_ws/src/lidar_cam_proj/calib/distortion.txt"

or

roslaunch lidar_cam_fuse lidar_cam_fuse.launch

Config

Calibration

Write your extrinsic, intrinsic & distortion parameters in .txt by following these format:

Note: The spaces between numbers are not important.

Extrinsic

-0.0090788  0.0851177   0.9963295   0.85383986
-0.9999462  -0.0057710  -0.0086187  0.154835
0.0050163   -0.9963542  0.0851655   1.03181427

Intrinsic

3974.66   0         934.31
0         3970.66   575.35
0         0         1.0

Distortion

-0.328462 0.078086 -0.004439 -0.000034 0.000000

Note: If the image is already undistorted (exp: images in KITTI), set all coefficients to 0:

0 0 0 0 0

Launch

To define the paths to required files, you edit launch/lidar_cam_fuse.launch

• out_dir: Directory where synchronized image, pointcloud & colored point cloud saved.
• bag: Path to the bag file.
• cam_topic: Topic to read messages from camera. (Currently, only support CompressedImage. You can change CompressedImage into Image to run with Image messages)
• lidar_topic: Topic to read messages from lidar.
• extrinsic/intrinsic/distortion: Paths to caliration files.

Debug

• Failed to find match for field 'rgb'. appears when we read a point cloud without rgb color. We dont need to worry about it.
• If the projection is completely wrong, it's likely due to the extrinsic params, the distortion and intrinsic params does not affect much the result.
• I strongly recommend using images with vertical, horizontal colored or a segmented ones to verify the accuracy of your projection.